Actually tearing is the least valuable feature of gsync. If you are worried about tearing all you need is fast sync, this is supported on 9 and 10 series of cards and it functions like vsync off but provides no tearing.
What makes gsync good is even at lower FPS the game is gonna look nice, thats why its a great investment in your PC. 3 years down the line a game comes out that you wanna play but you are only getting 50 fps, boom gsync no worries, game plays and looks good even at a lower FPS.